1. Field of the Invention
This invention relates to an elongate object cutting apparatus which is used to cut into fragments or small pieces a flexible elongate object such as a terminal carrier having a plurality of terminals connected in the form of a chain in a process of manufacturing a wire harness for use with an electric circuit or a wire, or an electric wire for use with a wire electrode electric discharge machine.
2. Description of the Prior Art
A process of manufacturing a wire harness includes the step of connecting a conductor and a terminal to each other. Normally at such connection step, a belt-shaped metal plate is worked by press work to form such a terminal chain c as seen in FIG. 7. Referring to FIG. 7, the terminal chain c includes a terminal carrier b to which a plurality of terminals a are connected in a predetermined spaced relationship from each other. Then, the terminal chain c is supplied to a press connection step for press connection to a conductor, or the like, to successively connect the terminals a to conductors, whereafter the terminal carrier b and the terminals a are cut away from each other. The terminal carrier b, thus cut away, is then cut into small pieces for the individual terminals a, and the thus cut small pieces are discharged.
An exemplary conventional apparatus for cutting such a flexible elongate member as the terminal carrier b described above into small pieces is shown in FIG. 8. In particular, in order to prevent the terminal carrier b from being scattered when it is cut into small pieces, the terminal carrier b is taken away, upon pressure connection thereof to a conductor, as it is, while it remains in the form of a belt without cutting it into individual small pieces, and then at another place, it is cut into and collected as small pieces in the form of chips using such a terminal carrier cutting apparatus K as shown in FIG. 8.
Referring to FIG. 8, the terminal carrier cutting apparatus K includes a sliding blade driving section d which is moved back and forth by a solenoid or a hydraulic cylinder, a sliding blade e connected to the sliding blade driving section d, a channel-shaped fixed blade f, and a sliding guide plate g. A chip box h is located below the sliding guide plate g for collecting small pieces in the form of chips cut from the terminal carrier b.
The terminal carrier b is supplied into an annular hole i defined by the channel-shaped fixed blade f and the sliding blade e, and the sliding blade e is moved back and forth in the directions indicated by a pair of arrow marks in FIG. 8 by the sliding blade driving section d.
In the terminal carrier cutting apparatus K described above, when the driving blade e is driven, the difference between a load operation condition and a no-load operation condition is so great that such vibrations or noises as may move the entire apparatus are produced. Further, where a solenoid is employed for the sliding plate driving section d, not only a timer, a relay and some other circuit elements are required for the electric circuit for the solenoid, but also a bad influence of electric noise is sometimes had on various elements around the apparatus.
Such a terminal carrier cutting apparatus as shown in FIG. 9 has been proposed in Japanese Patent Application No. Heisei 4-231919 by the assignee of the present invention.
Referring to FIG. 9, the terminal carrier cutting apparatus is denoted at L and is constructed such that a movable blade lever k is rocked around a support shaft m in accordance with rotation of a cam j which is driven by a motor so that a blade (not shown) provided at an edge of the movable blade lever k and a fixed blade n are repetitively moved into engagement and disengagement with and from each other to intermittently cut a carrier b supplied between the blade of the movable blade lever k and the fixed blade n.
Accordingly, the terminal carrier cutting apparatus L is advantageous in that it produces less vibrations and noises and is simple in structure and small in size as compared with the conventional wire electrode discharge machine described above with reference to FIG. 8 which involves back and forth movement of the sliding blade e. However, the terminal carrier cutting apparatus L still is limited as to increases of cutting speed and reduction in cutting length since cutting is performed by a rocking motion of the movable blade lever k. Consequently, the terminal carrier cutting apparatus L is disadvantageous in that enhancement of the productivity of the cutting step and fine cutting cannot be achieved.
A further exemplary flexible elongate object cutting apparatus is a cutting apparatus for cutting a wire used as an electrode of a wire electrode discharge machine.
A wire electrode discharge machine is constructed such that a wire for electrodes is normally fed by means of a supply reel and a take-up reel, and while discharge is produced between the wire and a metal mold secured on a work table, the work table is moved finely to perforate a hole of a predetermined shape into the metal mold.
The diameter of a wire used as electrodes normally ranges from approximately 0.1 to 0.3 mm, and a wire of about 5 kg wound on the supply reel is continuously supplied at the speed of 80 to 250 mm/sec.
In recent years, it is considered that, since a wire after use, drawn out from a discharge roller of a wire electrode discharge machine, cannot be re-used as it is, it is more advantageous to accommodate the wire directly from the discharge roller continuously and incontinently into a wire receiving vessel once without taking it up onto a take-up reel and then melting it collectively to re-use it. It is to be noted that it is generally inevitable to employ such incontinent accommodation four wire electrode discharge machines having an automatic wire connecting function.
In a wire electrode discharge machine of the incontinent accommodation type, if a wire after use is continuously accommodated into the wire receiving vessel, then the apparent specific gravity of the wire accumulated bulkily is as high as about one thirtieth, and the volume of the space occupied by the wire sometimes becomes so large that the wire may overflow from the vessel in a short period of time and wind itself around a discharge roller of the wire electrode discharge machine as the volume of the wire increases.
Accordingly, during operation, an operator must necessarily frequently watch a flow of a wire during use, and also the operation for regulating the flow is cumbersome and makes a factor of obstruction to automation.
It is, therefore, a possible idea to cut a wire after use into fragments or small pieces. A wire cutting apparatus for a discharge machine of the type just mentioned is disclosed, for example, in Japanese Utility Model Laid-Open Application No. Heisei 2-38141 and shown in FIG. 10.
Referring to FIG. 10, the wire cutting apparatus for a discharge machine shown is located at a terminal of a wire electrode discharge machine and constructed such that a wire r drawn out from the wire electrode discharge machine is cut into chips of the length of 6 cm by means of a rotary blade p mounted on a rotary shaft driven by a gear motor and a fixed blade q located in an opposing relationship to the rotary blade p, and the chips of the wire r are accommodated into a vessel prepared separately.
In particular, the wire r after use drawn out from the wire electrode discharge machine is guided by a guide tube s and is caught between a pair of feed rollers t. The wire r thus caught between the feed rollers t is fed downwardly along a side face of the fixed blade q and then nipped off into chips by the rotary blade p and the fixed blade q. The wire r in the form of chips drops along a guide plate u so that it is accommodated into a vessel located separately.
With the wire cutting apparatus M for a discharge machine, however, since frictional resistance by contact is present between the wire r after use drawn out from the wire electrode discharge machine and the inner face of the guide tube s, if the length of the guide tube s is increased, then it sometimes occurs that the guide tube s is jammed with the wire r, resulting in failure to continue operation of the apparatus.
Accordingly, the wire cutting apparatus M for a discharge machine must be located in the proximity of the wire discharging exit of the discharge machine. Consequently, the wire cutting apparatus M is disadvantageous in that an impact upon operation of the cutting blade thereof may be transmitted to the discharge machine and have a bad influence on the working accuracy of the discharge machine. Further, since cutting is performed by the single rotary blade p mounted on the rotary shaft, a single cutting operation is performed by a single rotation of the rotary shaft, and consequently, the length of chips after cut is as long as 6 cm. Accordingly, there is a disadvantage in that the volume of the space after the wire is discharged is not reduced very much and the operability for disposal of the wire is not improved remarkably.